1. Field of the Invention
The present invention relates to a heat-dissipating module. In particular, the present invention relates to a heat-dissipating module including a plurality of serially connected heat-dissipating fans.
2. Description of Related Art
FIG. 1 is an exploded perspective view of a conventional heat-dissipating module. FIG. 2 is a perspective view of the conventional heat-dissipating module. The heat-dissipating module includes a first fan unit 10, a second fan unit 20 that is serially connected to the first fan unit 10, and a stationary blade 30. The first fan unit 10 is located on the air inlet side, and the second fan unit 20 is located on the air outlet side. The stationary blade 30 is provided on a base portion of a casing 100 of the first fan unit 10 for guiding air current and for increasing the wind pressure. Generally, the casing 100 of the first fan unit 10 includes a plurality of engaging notches or grooves 111 and the casing 200 of the second fan unit 20 includes a plurality of engaging tabs 21 for engaging with the engaging grooves 11, thereby serially connecting the first fan unit 10 and the second fan unit 20 together. Thus, air is driven by a fan wheel (not shown) of the first fan unit 10 and a fan wheel 22 of the second fan unit 20, thereby rapidly blowing the air from the air inlet side to the air outlet side.
Although the amount of blown air and the velocity of the air are increased through the use of the above-mentioned heat-dissipating module, several problems still exist. Firstly, cool air can only be sucked into the heat-dissipating module via a single air inlet of the first fan unit 10 on the air inlet side under normal operation of the first fan unit 10 and the second fan unit 20. The overall air output amount is limited. Second, when the first fan unit 10 operates abnormally, the speed of the first fan wheel is lowered and thus adversely affects the air-blowing efficiency of the second fan wheel 22 and the overall heat-dissipating efficiency. Third, when the first fan unit 10 operates abnormally, the air density distribution is not uniform since the air velocity at the first fan wheel is different from that at the second fan wheel 22, resulting in poor static pressure-flow rate characteristics and poor P-Q characteristics and generating wind noise.
An object of the present invention is to provide a heat-dissipating module including two serially connected fan units and at least one side air inlet for introducing more air into the heat-dissipating module. The overall air inlet amount and the overall air outlet amount are increased, and the overall heat-dissipating efficiency is improved.
Another object of the present invention is to provide a heat-dissipating module include two serially connected fan units and at least one side air inlet for introducing more air into the heat-dissipating module when the first fan unit operates abnormally and thus fails to provide a sufficient air inlet amount. Non-uniform air density distribution in the heat-dissipating module is avoided, and the noise generated during operation of the heat-dissipating module is reduced. The overall heat-dissipating efficiency is thus improved.
To achieve the aforementioned objects, the present invention provides a heat-dissipating module including a first fan unit, a second fan unit, and connecting means for connecting the first fan unit and the second fan unit in a serial manner. The first fan unit is located on an air inlet side and includes a casing and a fan wheel received in the casing of the first fan unit. The second fan unit is located on an air outlet side and includes a casing and a fan wheel received in the casing of the second fan unit. At least one side air inlet is defined between the casing of the first fan unit and the casing of the second fan unit for increasing an air inlet amount and an air outlet amount of the second fan unit.
The air inlet amount and the air outlet amount of the second fan unit are increased. Thus, when the fan wheel of the first fan unit operates abnormally and thus results in a low air-blowing efficiency, the fan wheel of the second fan unit compensates the shortage of air inlet amount resulting in abnormal operation of the fan wheel of the first fan unit by introducing air into the heat-dissipating module via the side air inlet. The air density distribution is uniform, and the noise during operation is reduced.
Other objects, advantages and novel features of this invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.